Emmy Award-winning actress Marcia Wallace, who voiced the "Simpsons" role of Edna Krabappel and played wisecracking receptionist Carol Kester on the classic sitcom "The Bob Newhart Show," has died at the age of 70.

Wallace died at home in Los Angeles Friday night, surrounded by friends and family, said her son, Michael Hawley.

She had been in failing health for the last several months and died of complications due to pneumonia, Hawley said. Wallace, who had spoken widely about her battles with breast cancer, had surgery for it in March, after which she was considered clear of the disease, her son said.

The executive producer of "The Simpsons," Al Jean, said Saturday that the part of Mrs. Krabappel, the chain-smoking Springfield Elementary School teacher who was often driven to frustration by Bart Simpson, will be retired.

"I don't intend to have anyone else play Mrs. Krabappel," Jean said. "I think Bart will get a new teacher."

Wallace won a 1992 Emmy for her work on the long-running show. Jean said the next new episode, set to air Nov. 3, will include a tribute to the actress.

"She was sweet, funny, not at all pretentious," he said. "You fall in love with these people when you see them as characters on television, but when you met Marcia you loved her even more."

Word of her passing spread quickly on social media. "So sad to learn of the passing of the wonderful Marcia Wallace. Sorely missed already," tweeted Harry Shearer, who voices several characters on "The Simpsons."

Wallace, who had an acerbic wit and was known for her trademark red hair, had several television and stage roles and was a regular on talk shows before being cast as Carol Kester on the Bob Newhart sitcom that ran on CBS from 1972 to 1978.

"We were part of the culture of the '70s," said Wallace in a 1991 interview with The Times about her experience on the series. "I thought we had something really magical."

Hawley, 25, said his mother remained feisty and witty until near the end, even about her health setbacks. "The greatest gift she gave me was that you have to love the world, and see it through lenses of humor," he said.

Marcia Wallace was born Nov. 1, 1942, in Creston, Iowa. For someone so funny and optimistic, her childhood was far less than idyllic. In her 2004 autobiography, "Don't Look Back, We're Not Going That Way!" she wrote about growing up overweight and brainy, with alcoholic parents.

She began acting in high school and attended Parsons College in Fairfield, Iowa, where she majored in English and theater. The day she graduated, she moved to New York City.

"I weighed 230 pounds and I had $150 in the bank," Wallace wrote in her autobiography. "When people ask me, 'How do you break into show business?' I say, 'Well, first of all, your ready cash should at least equal your weight.'"

Wallace shed 100 pounds and by 1968 was appearing off-Broadway as member of the improvisation group The Fourth Wall.

A frequent guest on "The Merv Griffin Show" in New York, Wallace moved to Los Angeles when Griffin brought the program here. It was one of her appearances on the talk show that led to her being cast as the acerbic receptionist for button-down psychologist Bob Hartley on "The Bob Newhart Show."

Wallace also became a regular on popular game shows such as "Hollywood Squares" and "The $25,000 Pyramid." And after "Bob Newhart" ended, she guest-starred on many sitcoms, including "Full House," "Taxi" and "Murphy Brown." She also did theater, appearing in Los Angeles in "An Almost Perfect Person" and "The Vagina Monologues" and on tour in shows such as "Gypsy" and "Plaza Suite."

Her last role was in the not-yet-released film "Muffin Top: A Love Story," in which she appears with her son, also an actor and voice-over performer.

Wallace married Dennis Hawley in 1986. He died in 1992 of cancer.

"I have a deep conviction that our lives are eternal," she wrote. "I really do believe that Dennis and I will be together again, that we'll always be together in some mystical way."

In addition to her son, Wallace is survived by her sister, Sherry Wallace of Los Angeles, and a brother, Jimmy Wallace, who lives in Iowa.